Redis Info Command

Redis Server

The Redis Info command returns various information and statistical values about the Redis server in an easy-to-understand and readable format.

By providing an optional parameter section, the command can return only information about a specific part:

• server : General information about the Redis server, including the following fields:

• redis_version : The version of the Redis server

• redis_git_sha1 : Git SHA1

• redis_git_dirty : Git dirty flag

• os : The host operating system of the Redis server

• arch_bits : Architecture (32 or 64 (bit)

• multiplexing_api : The event handling mechanism used by Redis

• gcc_version : The GCC version used to compile Redis

• process_id : The PID of the server process

• run_id : The random identifier of the Redis server (used for Sentinel and cluster)

• tcp_port : TCP/IP Listening Port

• uptime_in_seconds : The number of seconds since the Redis server was started

• uptime_in_days : The number of days since the Redis server was started

• lru_clock : An incrementing clock in minutes used for LRU management

• clients : Information about connected clients, including the following fields:

• connected_clients : The number of connected clients (excluding clients connected through subordinate servers)

• client_longest_output_list : The longest output list of the currently connected client

• client_longest_input_buf : The largest input buffer of the currently connected client

• blocked_clients : The number of clients waiting for blocked commands (BLPOP, BRPOP, BRPOPLPUSH)

• memory : Memory information, including the following fields:

  In an ideal situation, the value of used_memory_rss should only be slightly higher than used_memory.

  When rss > used, and the difference between the two values is large, it indicates the existence of (internal or external) memory fragmentation.

  The ratio of memory fragmentation can be seen from the value of mem_fragmentation_ratio.

  When rss > used, it indicates that some of Redis's memory has been swapped out to the swap space by the operating system, and in this case, operations may produce noticeable delays.

  When Redis releases memory, the allocator may or may not return the memory to the operating system.

  If Redis releases memory but does not return it to the operating system, the value of used_memory may not be consistent with the Redis memory usage displayed by the operating system.

  Checking the value of used_memory_peak can verify whether this situation occurs.

• used_memory : The total amount of memory allocated by the Redis allocator, in bytes (byte)

• used_memory_human : Returns the total amount of memory allocated by Redis in a human-readable format

• used_memory_rss : From the perspective of the operating system, returns the total amount of memory allocated by Redis (commonly known as resident set size). This value is consistent with the output of commands like top and ps.

• used_memory_peak : The peak memory consumption of Redis (in bytes)

• used_memory_peak_human : Returns the peak memory consumption of Redis in a human-readable format

• used_memory_lua : The size of memory used by the Lua engine (in bytes)

• mem_fragmentation_ratio : The ratio between used_memory_rss and used_memory

• mem_allocator : The memory allocator specified at compile time, which Redis uses. It can be libc, jemalloc, or tcmalloc.

• persistence : Related information of RDB and AOF

• stats : General statistics information

• replication : Master/Replication information from the slave

• cpu : CPU computation statistics information

• commandstats : Redis command statistics information

• cluster : Redis cluster information

• keyspace : Statistics information related to the database

Syntax

The basic syntax of the redis Info command is as follows:

redis　127.0.0.1:6379>　INFO　[section]

Available version

>= 1.0.0

Return value

A collection of strings, text lines.

Online example

redis　127.0.0.1:6379>　INFO
# Server
redis_version:2.5.9
redis_git_sha1:473f3090
redis_git_dirty:0
os:Linux　3.3.7-1-ARCH　i686
arch_bits:32
multiplexing_api:epoll
gcc_version:4.7.0
process_id:8104
run_id:bc9e20c6f0aac67d0d396ab950940ae4d1479ad1
tcp_port:6379
uptime_in_seconds:7
uptime_in_days:0
lru_clock:1680564
# Clients
connected_clients:1
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0
# Memory
used_memory:439304
used_memory_human:429.01K
used_memory_rss:13897728
used_memory_peak:401776
used_memory_peak_human:392.36K
used_memory_lua:20480
mem_fragmentation_ratio:31.64
mem_allocator:jemalloc-3.0.0
# Persistence
loading:0
rdb_changes_since_last_save:0
rdb_bgsave_in_progress:0
rdb_last_save_time:1338011402
rdb_last_bgsave_status:ok
rdb_last_bgsave_time_sec:-1
rdb_current_bgsave_time_sec:-1
aof_enabled:0
aof_rewrite_in_progress:0
aof_rewrite_scheduled:0
aof_last_rewrite_time_sec:-1
aof_current_rewrite_time_sec:-1
# Stats
total_connections_received:1
total_commands_processed:0
instantaneous_ops_per_sec:0
rejected_connections:0
expired_keys:0
evicted_keys:0
keyspace_hits:0
keyspace_misses:0
pubsub_channels:0
pubsub_patterns:0
latest_fork_usec:0
# Replication
role:master
connected_slaves:0
# CPU
used_cpu_sys:0.03
used_cpu_user:0.01
used_cpu_sys_children:0.00
used_cpu_user_children:0.00
# Keyspace

Redis Server